The B7A Ryusei (originally designated AM-23 by Aichi) was designed in response to a 1941 16-Shi requirement issued by the Imperial Japanese Navy Air Service for a carrier attack bomber that would replace both the Nakajima B6N Tenzan torpedo plane and the Yokosuka D4Y Suisei dive bomber in IJN service. It was intended for use aboard a new generation of Taih?-class carriers, the first of which was laid down in July 1941. Because the deck elevators on the Taih?s had a larger square area than those of older Japanese carriers, the longstanding maximum limit of 11 m (36 ft) on carrier aircraft length could now be lifted.